ORC systems are generally well-known and commonly used for the purpose of generating electrical power that is provided to a power distribution system or grid for residential and commercial use across the country. These systems implement a vapor power cycle that utilizes an organic fluid as the working fluid instead of water/steam. Functionally these ORC systems resemble the steam cycle power plant, in which a pump increases the pressure of the condensed working fluid, the condensed working fluid is vaporized, and the vaporized working fluid interacts with a turbine to generate power.
Notably the ORC systems are generally closed-loop systems. However, systems of this type are particularly sensitive to changes in internal pressure because such changes can permit ingress of contaminants into the working fluid. These contaminants can not only reduce the efficiency of the ORC system, but also cause damage to one or more of the components that are used to implement the ORC cycle. Repairs, maintenance, and general cleaning of the system can be costly, as the ORC system must be taken off-line and thus no longer generates power that can be provided to the energy grid.
To avoid some issues of contamination, certain approaches utilize various forms of purge systems, which are fluidly coupled to the ORC system. These purge systems are typically configured to extract the working fluid from the ORC system, remove contaminants from the working fluid, and reintroduce the “clean” working fluid back into the ORC system. However, while this approach does address the issue of contamination, the purge systems require infrastructure, circuitry, and general structure that must be provided in addition to the components of the ORC system. This additional equipment can add cost and maintenance time to the ORC system. Moreover, the purge systems generally do not address the source of the contamination which is the ingress of contaminated fluids, such as air from the environment that surrounds the closed-loop ORC system.
There is therefore a need for an ORC system and method that can reduce the likelihood of the ingress of such contaminated air to address the issue of contamination in ORC systems at the source of the problem. There is likewise a need for solutions to the contamination issue that do not require the addition to the ORC system of substantially new equipment, costs, and control infrastructure.